1. Field of the Invention
The present invention relates to an electrical apparatus having a battery usable by repeating the charge and discharge function, and more particularly to an electrical apparatus in relation to a preliminary charging state.
2. Description of Related Art
For an information terminal equipment device, often represented by a notebook type personal computer (hereinafter referred to as a notebook PC), or various kinds of electrical apparatus such as a PDA (Personal Digital Assistant), an MD (Mini Disc) device, and/or a video camera, electric power is typically supplied directly from the commercial power supply, or from a rechargeable battery (battery, storage battery, secondary battery) that can be used many times over by simply repeating the charging and discharging of the battery. Such a battery, by way of example, may include a nickel hydride battery or a nickel cadmium battery (NiCd battery) that has relatively large capacity, and which is also typically inexpensive. In a further example, a lithium ion battery (having a higher energy density per unit weight than the nickel cadmium battery) and a lithium polymer battery, using the solid polymer without liquid electrolyte, are provided.
For this chargeable and dischargeable battery, an intelligent battery having a CPU inside a battery pack that is mounted on the electrical apparatus is widely employed. This intelligent battery may conform with the SBS (Smart Battery System), and communicate with a controller on the main unit side, employing an SBS protocol.
As is known, these batteries store electricity by the use of the chemical reaction, but involve a reversible range and an irreversible range as a result of the chemical reaction involved in the process of charging and discharging. If the discharge is made to a predetermined extent, the battery is restored to an originally charged state by supplying electricity from the outside. However, if the battery is discharged beyond a full discharge (discharge up to 100% of the rated capacity of battery), the battery becomes a so-called over-discharge to consume an electromotive force produced by a reaction other than the intrinsically reversible chemical reaction, resulting in an abnormally charged state even by charging.
In recovering the over-discharged battery, it is typically required to make the preliminary charge (trickle charge, pre-charge) of charging the battery at a low current before a quick charge so as not to damage the battery. If a fixed voltage value is reached in this preliminary charge, the quick charge is effected to make ordinary charge. This preliminary charge may be needed for about two hours depending on the extent of over-discharge of the battery.
However, in a conventional system, the preliminary charge and the quick charge are similarly handled. For even if a predetermined power supply meter displays that the charging is running, the user does not know that the preliminary charge is being performed. At such a time, an indication of a capacity of 0% is often displayed continuously during the two hours of preliminary charging, usually in a display. In such a case, the user may unknowingly exchange the normal battery by mistakenly assuming that a malfunction of not charging the battery has occurred. Furthermore, concerns also arise that as a result of the unobvious activity, a user may be inclined to make what actually is an otherwise unnecessary inquiry to a help center.
Moreover, in the SBS protocol, as cited above, though the data of displaying charging current value exists, when the current value is smaller, there is no interface indicating whether the current value is small immediately before the completion of charging, or the current value is small because of the preliminary charge that is a recovery from the over-discharge. Accordingly, it is not possible for the conventional system to distinguish between the preliminary charge and the quick charge even in the preliminary charging state at a stage of enabling the communication between the battery and the system.
Accordingly, there is a need for a preliminary charging state apparatus, program and method.
The present invention has been achieved to solve the above-mentioned technical problems, and it is an object of the invention to clearly identify the preliminary charging state in a battery.
Also, it is another object of the invention to provide an electrical apparatus having a battery in which the preliminary charging state is informed to the user.
To attain the above objects, the present invention provides an electrical apparatus that is capable of receiving a battery for supplying electric power to a main unit by discharging after charging, comprising preliminary charge judging means for judging whether or not the battery is in a preliminary charging state that is a recovery from over-discharge, and display means for displaying an indication of preliminary charging if the preliminary charge judging means judges that the battery is in the preliminary charging state.
The display means displays the remaining charging time including the time required for the preliminary charge and the time required for the quick charge that is made later, whereby it is possible to solve the problem that the user mistakes the fault despite the preliminary charging. Displaying the remaining charging time xe2x80x9cincludingxe2x80x9d the time required for the preliminary charge and the time required for the quick charge involves displaying one remaining charging time by adding both the charging times, displaying both at the same time or switching both.
The electrical apparatus to which the invention is applied comprises a main unit that consumes the electric power, and a battery for supplying electric power to the main unit by discharging after charging, wherein the main unit judges that the battery is in the preliminary charging state that is a recovery from over-discharge if a predetermined communication with the battery is disabled after confirming that the battery is connected while being charged, and displays the judged result.
Further, this invention provides a computer that is connectable to a battery for charging and discharging, in which an electric power is supplied from the battery connected to a system main unit. At this time, the system main unit comprises a battery connection confirmation terminal for confirming that the battery is connected, a controller that judges that the battery is in a preliminary charging state if a predetermined communication with the battery is disabled after acquiring the information indicating that the battery is connected from the battery connection confirmation terminal, and a display for displaying that the battery is in preliminary charging state if the controller judges that the battery is in the preliminary charging state.
From another aspect, a computer to which the invention is applied comprises preliminary charge judging means for judging whether or not the battery is in a preliminary charging state that is a recovery from over-discharge, and display means for displaying an indication of the preliminary charging if the preliminary charge judging means judges that the battery is in the preliminary charging state.
The preliminary charge judging means judges the preliminary charging, on the basis of the information acquired via a communication line from a CPU provided in the battery, if the remaining capacity of the battery is less than a predetermined amount (e.g., remaining capacity 10%) and electric current flowing through the battery is in a predetermined range (e.g., range from 0A to 0.5A), whereby it is possible to grasp the preliminary charging on the system side in the form in which a communication with the CPU is enabled even with over-discharge.
Further, the invention can be grasped as a preliminary charging state display method. That is, the preliminary charging state display method to which the invention is applied is used with an electrical apparatus that is connectable to a battery for discharging after charging, in which electric power is supplied from the battery to a main unit, the method comprising judging whether or not the battery is in a preliminary charging state that is a recovery from over-discharge, and displaying an indication of the preliminary charging state if the battery is judged to be in the preliminary charging state.
This invention can be designated as a utility program being executed on a computer capable of mounting a battery for supplying electric power by charging and discharging. That is, this invention can be grasped as the utility program for use with the computer connectable to the battery for discharging after charging, in which electric power is supplied from the battery to a main unit, the utility program comprising a function of acquiring the information indicating that the battery is in preliminary charging that is a recovery from over-discharge, and a function of displaying that the battery is in preliminary charging state if the information indicating that the battery is in preliminary charging is acquired.
This utility program suffices to implement the above functions on the computer. A method of providing this program may involve reading the program stored in the storage medium such as a CD-ROM in a reader section for the storage medium such as a CD-ROM drive. Also, the program may be installed from the program transmission device via a network such as the Internet into the computer.